Need a little insight, waiting for my doctor to call back..

So today , I had work at 8am, I ate a bowl of cereal and had a glass of grape juice right before going to work. Started my shift at 7:54, went to my check stand ( I am a cashier) & I started feeling really dizzy, so I drank some water. Cashed out a few more people;& than I started getting blurry vision and I blacked out couldn't see anything, while I was in yhe middle of checking someone out, while bagging their groceries (bread) I start to be unable to see so I stumbled . Apologized to the guy and gave him his change. I turned off my light, & told another cashier I felt like I was about to pass out, she told me to go sit, so I walked over to behind the customer service desk, where no one could see me and I sat down in the chair, and put my head down. Next thing I know I'm nauseous, and I throw up on my pants and reach for a trash can, and finish in their. I clean up my mess and got someone to cover my shift. Anyways.. this is the 2nd time this has happened in less than 2 weeks, first time I was just sitting at home. (I'm 14 weeks pregnant)

Any idea on what's going on? My doctor hasn't called back yet.